Psychomotor stimulant drugs of abuse cause brain damage that is dependent on elevated body temperature. This year, we continued to examine brain and body temperature changes in relation to the permeability of brain-blood barrier during exposure to meth-amphetamine. We found that meth-amphetamine induces the leakage of brain-blood barrier and the degree of damage depends on drug-induced increase of brain temperature. We also continue our studies of the central mechanisms underlying addictive properties of cocaine and its physiological effects. Particularly, we compared brain temperature effects of iv cocaine with those induced by procaine, a structurally-similar local anesthetic drug, and cocaine methiodide, a cocaine?s derivative that fails to cross blood-brain barrier. We found that all three drugs have similarities in inducing rapid brain temperature increase, implicating peripheral Na+ channels as an important substrate involved in mediating the acute stimulatory effects of iv cocaine. Finally, we also continued our studies of dopamine mechanisms and their role in mediating locomotor stimulatory and reinforcing effects of cocaine. Our thermorecording work with selective dopamine agonists (i.e., apomorphine) and antagonists was supplemented by our parallel electrophysiological studies, using single-unit recording with iontophoresis in awake rats. This approach appears to be an important tool for the study of central mechanisms of action of various drugs of abuse and drug-taking behavior. It provides novel information to examine the role of environmental factors in adverse health effects of addictive drug use.